chrisc Posted June 7, 2023 Share Posted June 7, 2023 Friend acquired a RTC/Axpert 5kW inverter and new 48 volt battery On connecting battery, inverter started. Output priority set to Util Display shows BYPASS with 230V in and 230V out. Battery charged to 54 volts Turn off mains power and output goes to 0V straight away, ie it does not convert battery power to AC Any pointers, or is it a job for a professional repairer? Quote Link to comment Share on other sites More sharing options...
Coulomb Posted June 8, 2023 Share Posted June 8, 2023 4 hours ago, chrisc said: Any pointers, Perhaps try it with output source priority set to SBU. I agree that your test above should have resulted in the battery taking over. What does the inverter say that the battery voltage is? How does that compare to what a multimeter says? Quote Link to comment Share on other sites More sharing options...
Deon Zeelie Posted June 8, 2023 Share Posted June 8, 2023 Sitting with same problem today for some reason. Battery is as 48%, but inverter stays on line, disabled the solar assistant power function, set inverter to sbu but it stays on bypass. If I trip the line it does switch over to battery. Any idea what can be wrong Quote Link to comment Share on other sites More sharing options...
Deon Zeelie Posted June 8, 2023 Share Posted June 8, 2023 Thank you for the voltage reminder Coulomb, I was looking at the Solar Assistant power management graph % but my voltage was below the back to battery setting. Quote Link to comment Share on other sites More sharing options...
Coulomb Posted June 8, 2023 Share Posted June 8, 2023 (edited) 7 hours ago, Deon Zeelie said: If I trip the line it does switch over to battery. Any idea what can be wrong This is a hassle of the "lead acid thinking" inherent in the firmware. Though maybe you actually have a lead acid battery. It wants to charge the lead acid (whether it actually is lead-acid or not) battery up to something like 2.0 V more than the back to utility voltage before it declares the battery "no longer weak". 7 hours ago, Deon Zeelie said: Battery is as 48% If that's from the inverter's data (possibly as interpreted by monitoring software), then it's not very accurate, being based on voltage, and not compensated for load or charging effects. If you have an LFP battery, then it's almost worthless; it just tells you it's not nearly full or nearly empty. Everything from 20% SoC to 80% Soc on an LFP battery looks to the voltage based guesstimate to be a middling SoC. If you have an LFP battery and a 145 V max PV inverter model, then you can mitigate a lot of these hassles with an LFP flavour of patched firmware; see the AEVA page: https://forums.aeva.asn.au/viewtopic.php?t=4332#firmware Edited June 8, 2023 by Coulomb Quote Link to comment Share on other sites More sharing options...
chrisc Posted June 8, 2023 Author Share Posted June 8, 2023 The battery voltage measured at the terminals is 53.6V. The display states 54V Whatever value is used for Source, the inverter won't produce AC The battery type is set to "USE" with bulk charge to 54.6 and float 54.0 Quote Link to comment Share on other sites More sharing options...
Flouw Posted June 8, 2023 Share Posted June 8, 2023 is there a setting 04? and what load is on the output on the AC when you do kill the input? you also say "acquired," so he got it for free, or bought it second hand? perhaps a faulty/damaged unit? run through all the settings. if its setting related, im sure you or we will see it once revealed. Quote Link to comment Share on other sites More sharing options...
JacquesV Posted June 8, 2023 Share Posted June 8, 2023 If it is a "AXPERT KING 5KW" the round power button on the removable display might be pressed causing it to go on bypass. Quote Link to comment Share on other sites More sharing options...
Coulomb Posted June 9, 2023 Share Posted June 9, 2023 4 hours ago, JacquesV said: the round power button on the removable display might be pressed causing it to go on bypass. There is a setting, setting 23 ("Bypass function") that seems to determine the way the power switch works. In the default position (ByE), it seems that you can power the loads from AC-in even with the power switch off. But with the ByD choice for this setting, the inverter won't go to bypass mode and the loads will go off immediately. So @chrisc, perhaps check this setting and the power switch. I don't know what this setting would be called in monitoring software, if the monitoring software handles that setting at all. And perhaps you don't want to change it anyway. Quote Link to comment Share on other sites More sharing options...
JacquesV Posted June 9, 2023 Share Posted June 9, 2023 (edited) 56 minutes ago, Coulomb said: There is a setting, setting 23 ("Bypass function") that seems to determine the way the power switch works. In the default position (ByE), it seems that you can power the loads from AC-in even with the power switch off. But with the ByD choice for this setting, the inverter won't go to bypass mode and the loads will go off immediately. So @chrisc, perhaps check this setting and the power switch. I don't know what this setting would be called in monitoring software, if the monitoring software handles that setting at all. And perhaps you don't want to change it anyway. Yes indeed it does. If switch is pressed in, it goes to battery mode when mains fail, depressed the load disconnects or switches off. With ByE the load is powered by mains and not the inverter losing mains the load disconnects and does not use battery power through the inverter (hopes this makes sense). I never changed setting 23 via ICC or ICM, don't think it can be set via these control systems, but I might be wrong. Edited June 9, 2023 by JacquesV Quote Link to comment Share on other sites More sharing options...
chrisc Posted June 9, 2023 Author Share Posted June 9, 2023 (edited) Location 23 is set to Byd (default according to the manual) The on/off switch is bottom right The inverter was bought in 2019, intended to be used in a holiday house which never materialised, so the owner decided to use it at home Edited June 9, 2023 by chrisc Quote Link to comment Share on other sites More sharing options...
Coulomb Posted June 11, 2023 Share Posted June 11, 2023 Is the battery perhaps very weak? Being charged to 54 V doesn't mean much, if it has a high internal resistance. Get the owner to report the battery voltage immediately after the utility is disconnected. If it briefly plummets to say 41 V, then that would be the problem. Note that a battery with high internal resistance could well bounce back to say 50 V if it has no load, so the owner needs to watch carefully and perhaps repeat the experiment a few times. Quote Link to comment Share on other sites More sharing options...
chrisc Posted June 17, 2023 Author Share Posted June 17, 2023 (edited) Fitted another inverter to the same battery and it works 100% Found a repairer in Cape Town who will repair it Edited June 17, 2023 by chrisc Quote Link to comment Share on other sites More sharing options...
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